#include <stdio.h>
#include <math.h>

int main(void)
{
	int m, n, i;

	printf("Input an integer greater than 1: ");
	scanf("%d", &n);
	m = (int)(sqrt(n) + 1);
	for (i = 2; i < m; i++)
		if (n % i == 0)
			break;
	if (i == m)
		printf("%d is a prime number.\n", n);
	else
		printf("%d is not a prime number.\n", n);

	return 0;
}